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7c97f91e MM |
1 | /* Linux-dependent part of branch trace support for GDB, and GDBserver. |
2 | ||
61baf725 | 3 | Copyright (C) 2013-2017 Free Software Foundation, Inc. |
7c97f91e MM |
4 | |
5 | Contributed by Intel Corp. <markus.t.metzger@intel.com> | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
21 | ||
53f81362 | 22 | #include "common-defs.h" |
7c97f91e | 23 | #include "linux-btrace.h" |
361c8ade | 24 | #include "common-regcache.h" |
be8b1ea6 | 25 | #include "gdb_wait.h" |
df7e5265 | 26 | #include "x86-cpuid.h" |
0568462b MM |
27 | #include "filestuff.h" |
28 | ||
29 | #include <inttypes.h> | |
7c97f91e | 30 | |
5b4e221c MF |
31 | #ifdef HAVE_SYS_SYSCALL_H |
32 | #include <sys/syscall.h> | |
33 | #endif | |
34 | ||
35 | #if HAVE_LINUX_PERF_EVENT_H && defined(SYS_perf_event_open) | |
7c97f91e | 36 | #include <unistd.h> |
7c97f91e MM |
37 | #include <sys/mman.h> |
38 | #include <sys/user.h> | |
5826e159 | 39 | #include "nat/gdb_ptrace.h" |
a950d57c | 40 | #include <sys/types.h> |
a950d57c | 41 | #include <signal.h> |
7c97f91e MM |
42 | |
43 | /* A branch trace record in perf_event. */ | |
44 | struct perf_event_bts | |
45 | { | |
46 | /* The linear address of the branch source. */ | |
47 | uint64_t from; | |
48 | ||
49 | /* The linear address of the branch destination. */ | |
50 | uint64_t to; | |
51 | }; | |
52 | ||
53 | /* A perf_event branch trace sample. */ | |
54 | struct perf_event_sample | |
55 | { | |
56 | /* The perf_event sample header. */ | |
57 | struct perf_event_header header; | |
58 | ||
59 | /* The perf_event branch tracing payload. */ | |
60 | struct perf_event_bts bts; | |
61 | }; | |
62 | ||
afb778a2 MM |
63 | /* Identify the cpu we're running on. */ |
64 | static struct btrace_cpu | |
65 | btrace_this_cpu (void) | |
66 | { | |
67 | struct btrace_cpu cpu; | |
68 | unsigned int eax, ebx, ecx, edx; | |
69 | int ok; | |
70 | ||
71 | memset (&cpu, 0, sizeof (cpu)); | |
72 | ||
73 | ok = x86_cpuid (0, &eax, &ebx, &ecx, &edx); | |
74 | if (ok != 0) | |
75 | { | |
76 | if (ebx == signature_INTEL_ebx && ecx == signature_INTEL_ecx | |
77 | && edx == signature_INTEL_edx) | |
78 | { | |
79 | unsigned int cpuid, ignore; | |
80 | ||
81 | ok = x86_cpuid (1, &cpuid, &ignore, &ignore, &ignore); | |
82 | if (ok != 0) | |
83 | { | |
84 | cpu.vendor = CV_INTEL; | |
85 | ||
86 | cpu.family = (cpuid >> 8) & 0xf; | |
87 | cpu.model = (cpuid >> 4) & 0xf; | |
88 | ||
89 | if (cpu.family == 0x6) | |
90 | cpu.model += (cpuid >> 12) & 0xf0; | |
91 | } | |
92 | } | |
93 | } | |
94 | ||
95 | return cpu; | |
96 | } | |
97 | ||
aadf7753 | 98 | /* Return non-zero if there is new data in PEVENT; zero otherwise. */ |
7c97f91e | 99 | |
aadf7753 MM |
100 | static int |
101 | perf_event_new_data (const struct perf_event_buffer *pev) | |
7c97f91e | 102 | { |
aadf7753 | 103 | return *pev->data_head != pev->last_head; |
7c97f91e MM |
104 | } |
105 | ||
b20a6524 MM |
106 | /* Copy the last SIZE bytes from PEV ending at DATA_HEAD and return a pointer |
107 | to the memory holding the copy. | |
108 | The caller is responsible for freeing the memory. */ | |
109 | ||
110 | static gdb_byte * | |
e7b01ce0 MM |
111 | perf_event_read (const struct perf_event_buffer *pev, __u64 data_head, |
112 | size_t size) | |
b20a6524 MM |
113 | { |
114 | const gdb_byte *begin, *end, *start, *stop; | |
115 | gdb_byte *buffer; | |
e7b01ce0 MM |
116 | size_t buffer_size; |
117 | __u64 data_tail; | |
b20a6524 MM |
118 | |
119 | if (size == 0) | |
120 | return NULL; | |
121 | ||
db58b373 MM |
122 | /* We should never ask for more data than the buffer can hold. */ |
123 | buffer_size = pev->size; | |
124 | gdb_assert (size <= buffer_size); | |
125 | ||
126 | /* If we ask for more data than we seem to have, we wrap around and read | |
127 | data from the end of the buffer. This is already handled by the % | |
128 | BUFFER_SIZE operation, below. Here, we just need to make sure that we | |
129 | don't underflow. | |
130 | ||
131 | Note that this is perfectly OK for perf event buffers where data_head | |
132 | doesn'grow indefinitely and instead wraps around to remain within the | |
133 | buffer's boundaries. */ | |
134 | if (data_head < size) | |
135 | data_head += buffer_size; | |
136 | ||
b20a6524 MM |
137 | gdb_assert (size <= data_head); |
138 | data_tail = data_head - size; | |
139 | ||
b20a6524 MM |
140 | begin = pev->mem; |
141 | start = begin + data_tail % buffer_size; | |
142 | stop = begin + data_head % buffer_size; | |
143 | ||
224c3ddb | 144 | buffer = (gdb_byte *) xmalloc (size); |
b20a6524 MM |
145 | |
146 | if (start < stop) | |
147 | memcpy (buffer, start, stop - start); | |
148 | else | |
149 | { | |
150 | end = begin + buffer_size; | |
151 | ||
152 | memcpy (buffer, start, end - start); | |
153 | memcpy (buffer + (end - start), begin, stop - begin); | |
154 | } | |
155 | ||
156 | return buffer; | |
157 | } | |
158 | ||
159 | /* Copy the perf event buffer data from PEV. | |
160 | Store a pointer to the copy into DATA and its size in SIZE. */ | |
161 | ||
162 | static void | |
163 | perf_event_read_all (struct perf_event_buffer *pev, gdb_byte **data, | |
e7b01ce0 | 164 | size_t *psize) |
b20a6524 | 165 | { |
e7b01ce0 MM |
166 | size_t size; |
167 | __u64 data_head; | |
b20a6524 MM |
168 | |
169 | data_head = *pev->data_head; | |
b20a6524 | 170 | size = pev->size; |
b20a6524 MM |
171 | |
172 | *data = perf_event_read (pev, data_head, size); | |
173 | *psize = size; | |
174 | ||
175 | pev->last_head = data_head; | |
176 | } | |
177 | ||
178 | /* Determine the event type. | |
179 | Returns zero on success and fills in TYPE; returns -1 otherwise. */ | |
180 | ||
181 | static int | |
182 | perf_event_pt_event_type (int *type) | |
183 | { | |
184 | FILE *file; | |
185 | int found; | |
186 | ||
187 | file = fopen ("/sys/bus/event_source/devices/intel_pt/type", "r"); | |
188 | if (file == NULL) | |
189 | return -1; | |
190 | ||
191 | found = fscanf (file, "%d", type); | |
192 | ||
193 | fclose (file); | |
194 | ||
195 | if (found == 1) | |
196 | return 0; | |
197 | return -1; | |
198 | } | |
199 | ||
0568462b MM |
200 | /* Try to determine the start address of the Linux kernel. */ |
201 | ||
202 | static uint64_t | |
203 | linux_determine_kernel_start (void) | |
d68e53f4 | 204 | { |
0568462b MM |
205 | static uint64_t kernel_start; |
206 | static int cached; | |
207 | FILE *file; | |
d68e53f4 | 208 | |
0568462b MM |
209 | if (cached != 0) |
210 | return kernel_start; | |
d68e53f4 | 211 | |
0568462b MM |
212 | cached = 1; |
213 | ||
214 | file = gdb_fopen_cloexec ("/proc/kallsyms", "r"); | |
215 | if (file == NULL) | |
216 | return kernel_start; | |
217 | ||
218 | while (!feof (file)) | |
219 | { | |
220 | char buffer[1024], symbol[8], *line; | |
221 | uint64_t addr; | |
222 | int match; | |
223 | ||
224 | line = fgets (buffer, sizeof (buffer), file); | |
225 | if (line == NULL) | |
226 | break; | |
d68e53f4 | 227 | |
0568462b MM |
228 | match = sscanf (line, "%" SCNx64 " %*[tT] %7s", &addr, symbol); |
229 | if (match != 2) | |
230 | continue; | |
d68e53f4 | 231 | |
0568462b MM |
232 | if (strcmp (symbol, "_text") == 0) |
233 | { | |
234 | kernel_start = addr; | |
235 | break; | |
236 | } | |
237 | } | |
238 | ||
239 | fclose (file); | |
240 | ||
241 | return kernel_start; | |
d68e53f4 MM |
242 | } |
243 | ||
7c97f91e MM |
244 | /* Check whether an address is in the kernel. */ |
245 | ||
246 | static inline int | |
0568462b | 247 | perf_event_is_kernel_addr (uint64_t addr) |
7c97f91e | 248 | { |
0568462b | 249 | uint64_t kernel_start; |
7c97f91e | 250 | |
0568462b MM |
251 | kernel_start = linux_determine_kernel_start (); |
252 | if (kernel_start != 0ull) | |
253 | return (addr >= kernel_start); | |
7c97f91e | 254 | |
0568462b MM |
255 | /* If we don't know the kernel's start address, let's check the most |
256 | significant bit. This will work at least for 64-bit kernels. */ | |
257 | return ((addr & (1ull << 63)) != 0); | |
7c97f91e MM |
258 | } |
259 | ||
260 | /* Check whether a perf event record should be skipped. */ | |
261 | ||
262 | static inline int | |
0568462b | 263 | perf_event_skip_bts_record (const struct perf_event_bts *bts) |
7c97f91e MM |
264 | { |
265 | /* The hardware may report branches from kernel into user space. Branches | |
266 | from user into kernel space will be suppressed. We filter the former to | |
267 | provide a consistent branch trace excluding kernel. */ | |
0568462b | 268 | return perf_event_is_kernel_addr (bts->from); |
7c97f91e MM |
269 | } |
270 | ||
271 | /* Perform a few consistency checks on a perf event sample record. This is | |
272 | meant to catch cases when we get out of sync with the perf event stream. */ | |
273 | ||
274 | static inline int | |
275 | perf_event_sample_ok (const struct perf_event_sample *sample) | |
276 | { | |
277 | if (sample->header.type != PERF_RECORD_SAMPLE) | |
278 | return 0; | |
279 | ||
280 | if (sample->header.size != sizeof (*sample)) | |
281 | return 0; | |
282 | ||
283 | return 1; | |
284 | } | |
285 | ||
286 | /* Branch trace is collected in a circular buffer [begin; end) as pairs of from | |
287 | and to addresses (plus a header). | |
288 | ||
289 | Start points into that buffer at the next sample position. | |
290 | We read the collected samples backwards from start. | |
291 | ||
292 | While reading the samples, we convert the information into a list of blocks. | |
293 | For two adjacent samples s1 and s2, we form a block b such that b.begin = | |
294 | s1.to and b.end = s2.from. | |
295 | ||
296 | In case the buffer overflows during sampling, one sample may have its lower | |
297 | part at the end and its upper part at the beginning of the buffer. */ | |
298 | ||
299 | static VEC (btrace_block_s) * | |
300 | perf_event_read_bts (struct btrace_target_info* tinfo, const uint8_t *begin, | |
e7b01ce0 | 301 | const uint8_t *end, const uint8_t *start, size_t size) |
7c97f91e MM |
302 | { |
303 | VEC (btrace_block_s) *btrace = NULL; | |
304 | struct perf_event_sample sample; | |
e7b01ce0 | 305 | size_t read = 0; |
7c97f91e MM |
306 | struct btrace_block block = { 0, 0 }; |
307 | struct regcache *regcache; | |
308 | ||
309 | gdb_assert (begin <= start); | |
310 | gdb_assert (start <= end); | |
311 | ||
312 | /* The first block ends at the current pc. */ | |
361c8ade | 313 | regcache = get_thread_regcache_for_ptid (tinfo->ptid); |
7c97f91e MM |
314 | block.end = regcache_read_pc (regcache); |
315 | ||
316 | /* The buffer may contain a partial record as its last entry (i.e. when the | |
317 | buffer size is not a multiple of the sample size). */ | |
318 | read = sizeof (sample) - 1; | |
319 | ||
320 | for (; read < size; read += sizeof (sample)) | |
321 | { | |
322 | const struct perf_event_sample *psample; | |
323 | ||
324 | /* Find the next perf_event sample in a backwards traversal. */ | |
325 | start -= sizeof (sample); | |
326 | ||
327 | /* If we're still inside the buffer, we're done. */ | |
328 | if (begin <= start) | |
329 | psample = (const struct perf_event_sample *) start; | |
330 | else | |
331 | { | |
332 | int missing; | |
333 | ||
334 | /* We're to the left of the ring buffer, we will wrap around and | |
335 | reappear at the very right of the ring buffer. */ | |
336 | ||
337 | missing = (begin - start); | |
338 | start = (end - missing); | |
339 | ||
340 | /* If the entire sample is missing, we're done. */ | |
341 | if (missing == sizeof (sample)) | |
342 | psample = (const struct perf_event_sample *) start; | |
343 | else | |
344 | { | |
345 | uint8_t *stack; | |
346 | ||
347 | /* The sample wrapped around. The lower part is at the end and | |
348 | the upper part is at the beginning of the buffer. */ | |
349 | stack = (uint8_t *) &sample; | |
350 | ||
351 | /* Copy the two parts so we have a contiguous sample. */ | |
352 | memcpy (stack, start, missing); | |
353 | memcpy (stack + missing, begin, sizeof (sample) - missing); | |
354 | ||
355 | psample = &sample; | |
356 | } | |
357 | } | |
358 | ||
359 | if (!perf_event_sample_ok (psample)) | |
360 | { | |
361 | warning (_("Branch trace may be incomplete.")); | |
362 | break; | |
363 | } | |
364 | ||
0568462b | 365 | if (perf_event_skip_bts_record (&psample->bts)) |
7c97f91e MM |
366 | continue; |
367 | ||
368 | /* We found a valid sample, so we can complete the current block. */ | |
369 | block.begin = psample->bts.to; | |
370 | ||
371 | VEC_safe_push (btrace_block_s, btrace, &block); | |
372 | ||
373 | /* Start the next block. */ | |
374 | block.end = psample->bts.from; | |
375 | } | |
376 | ||
969c39fb MM |
377 | /* Push the last block (i.e. the first one of inferior execution), as well. |
378 | We don't know where it ends, but we know where it starts. If we're | |
379 | reading delta trace, we can fill in the start address later on. | |
380 | Otherwise we will prune it. */ | |
381 | block.begin = 0; | |
382 | VEC_safe_push (btrace_block_s, btrace, &block); | |
383 | ||
7c97f91e MM |
384 | return btrace; |
385 | } | |
386 | ||
043c3577 | 387 | /* Check whether the kernel supports BTS. */ |
a950d57c MM |
388 | |
389 | static int | |
043c3577 | 390 | kernel_supports_bts (void) |
a950d57c MM |
391 | { |
392 | struct perf_event_attr attr; | |
393 | pid_t child, pid; | |
394 | int status, file; | |
395 | ||
396 | errno = 0; | |
397 | child = fork (); | |
398 | switch (child) | |
399 | { | |
400 | case -1: | |
76fb6829 | 401 | warning (_("test bts: cannot fork: %s."), safe_strerror (errno)); |
a950d57c MM |
402 | return 0; |
403 | ||
404 | case 0: | |
405 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
406 | if (status != 0) | |
407 | { | |
043c3577 | 408 | warning (_("test bts: cannot PTRACE_TRACEME: %s."), |
76fb6829 | 409 | safe_strerror (errno)); |
a950d57c MM |
410 | _exit (1); |
411 | } | |
412 | ||
413 | status = raise (SIGTRAP); | |
414 | if (status != 0) | |
415 | { | |
043c3577 | 416 | warning (_("test bts: cannot raise SIGTRAP: %s."), |
76fb6829 | 417 | safe_strerror (errno)); |
a950d57c MM |
418 | _exit (1); |
419 | } | |
420 | ||
421 | _exit (1); | |
422 | ||
423 | default: | |
424 | pid = waitpid (child, &status, 0); | |
425 | if (pid != child) | |
426 | { | |
043c3577 | 427 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 428 | (long) pid, safe_strerror (errno)); |
a950d57c MM |
429 | return 0; |
430 | } | |
431 | ||
432 | if (!WIFSTOPPED (status)) | |
433 | { | |
043c3577 | 434 | warning (_("test bts: expected stop. status: %d."), |
a950d57c MM |
435 | status); |
436 | return 0; | |
437 | } | |
438 | ||
439 | memset (&attr, 0, sizeof (attr)); | |
440 | ||
441 | attr.type = PERF_TYPE_HARDWARE; | |
442 | attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
443 | attr.sample_period = 1; | |
444 | attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
445 | attr.exclude_kernel = 1; | |
446 | attr.exclude_hv = 1; | |
447 | attr.exclude_idle = 1; | |
448 | ||
449 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
450 | if (file >= 0) | |
451 | close (file); | |
452 | ||
453 | kill (child, SIGKILL); | |
454 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
455 | ||
456 | pid = waitpid (child, &status, 0); | |
457 | if (pid != child) | |
458 | { | |
043c3577 | 459 | warning (_("test bts: bad pid %ld, error: %s."), |
76fb6829 | 460 | (long) pid, safe_strerror (errno)); |
a950d57c | 461 | if (!WIFSIGNALED (status)) |
043c3577 | 462 | warning (_("test bts: expected killed. status: %d."), |
a950d57c MM |
463 | status); |
464 | } | |
465 | ||
466 | return (file >= 0); | |
467 | } | |
468 | } | |
469 | ||
bc504a31 | 470 | /* Check whether the kernel supports Intel Processor Trace. */ |
b20a6524 MM |
471 | |
472 | static int | |
473 | kernel_supports_pt (void) | |
474 | { | |
475 | struct perf_event_attr attr; | |
476 | pid_t child, pid; | |
477 | int status, file, type; | |
478 | ||
479 | errno = 0; | |
480 | child = fork (); | |
481 | switch (child) | |
482 | { | |
483 | case -1: | |
76fb6829 | 484 | warning (_("test pt: cannot fork: %s."), safe_strerror (errno)); |
b20a6524 MM |
485 | return 0; |
486 | ||
487 | case 0: | |
488 | status = ptrace (PTRACE_TRACEME, 0, NULL, NULL); | |
489 | if (status != 0) | |
490 | { | |
491 | warning (_("test pt: cannot PTRACE_TRACEME: %s."), | |
76fb6829 | 492 | safe_strerror (errno)); |
b20a6524 MM |
493 | _exit (1); |
494 | } | |
495 | ||
496 | status = raise (SIGTRAP); | |
497 | if (status != 0) | |
498 | { | |
499 | warning (_("test pt: cannot raise SIGTRAP: %s."), | |
76fb6829 | 500 | safe_strerror (errno)); |
b20a6524 MM |
501 | _exit (1); |
502 | } | |
503 | ||
504 | _exit (1); | |
505 | ||
506 | default: | |
507 | pid = waitpid (child, &status, 0); | |
508 | if (pid != child) | |
509 | { | |
510 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 511 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
512 | return 0; |
513 | } | |
514 | ||
515 | if (!WIFSTOPPED (status)) | |
516 | { | |
517 | warning (_("test pt: expected stop. status: %d."), | |
518 | status); | |
519 | return 0; | |
520 | } | |
521 | ||
522 | status = perf_event_pt_event_type (&type); | |
523 | if (status != 0) | |
524 | file = -1; | |
525 | else | |
526 | { | |
527 | memset (&attr, 0, sizeof (attr)); | |
528 | ||
529 | attr.size = sizeof (attr); | |
530 | attr.type = type; | |
531 | attr.exclude_kernel = 1; | |
532 | attr.exclude_hv = 1; | |
533 | attr.exclude_idle = 1; | |
534 | ||
535 | file = syscall (SYS_perf_event_open, &attr, child, -1, -1, 0); | |
536 | if (file >= 0) | |
537 | close (file); | |
538 | } | |
539 | ||
540 | kill (child, SIGKILL); | |
541 | ptrace (PTRACE_KILL, child, NULL, NULL); | |
542 | ||
543 | pid = waitpid (child, &status, 0); | |
544 | if (pid != child) | |
545 | { | |
546 | warning (_("test pt: bad pid %ld, error: %s."), | |
76fb6829 | 547 | (long) pid, safe_strerror (errno)); |
b20a6524 MM |
548 | if (!WIFSIGNALED (status)) |
549 | warning (_("test pt: expected killed. status: %d."), | |
550 | status); | |
551 | } | |
552 | ||
553 | return (file >= 0); | |
554 | } | |
555 | } | |
556 | ||
043c3577 | 557 | /* Check whether an Intel cpu supports BTS. */ |
a950d57c MM |
558 | |
559 | static int | |
afb778a2 | 560 | intel_supports_bts (const struct btrace_cpu *cpu) |
a950d57c | 561 | { |
afb778a2 | 562 | switch (cpu->family) |
5f8e0b8f MF |
563 | { |
564 | case 0x6: | |
afb778a2 | 565 | switch (cpu->model) |
5f8e0b8f MF |
566 | { |
567 | case 0x1a: /* Nehalem */ | |
568 | case 0x1f: | |
569 | case 0x1e: | |
570 | case 0x2e: | |
571 | case 0x25: /* Westmere */ | |
572 | case 0x2c: | |
573 | case 0x2f: | |
574 | case 0x2a: /* Sandy Bridge */ | |
575 | case 0x2d: | |
576 | case 0x3a: /* Ivy Bridge */ | |
577 | ||
578 | /* AAJ122: LBR, BTM, or BTS records may have incorrect branch | |
579 | "from" information afer an EIST transition, T-states, C1E, or | |
580 | Adaptive Thermal Throttling. */ | |
581 | return 0; | |
582 | } | |
583 | } | |
a950d57c MM |
584 | |
585 | return 1; | |
a950d57c MM |
586 | } |
587 | ||
043c3577 | 588 | /* Check whether the cpu supports BTS. */ |
a950d57c MM |
589 | |
590 | static int | |
043c3577 | 591 | cpu_supports_bts (void) |
a950d57c | 592 | { |
afb778a2 | 593 | struct btrace_cpu cpu; |
a950d57c | 594 | |
afb778a2 MM |
595 | cpu = btrace_this_cpu (); |
596 | switch (cpu.vendor) | |
597 | { | |
598 | default: | |
599 | /* Don't know about others. Let's assume they do. */ | |
600 | return 1; | |
a950d57c | 601 | |
afb778a2 MM |
602 | case CV_INTEL: |
603 | return intel_supports_bts (&cpu); | |
604 | } | |
a950d57c MM |
605 | } |
606 | ||
043c3577 | 607 | /* Check whether the linux target supports BTS. */ |
7c97f91e | 608 | |
043c3577 MM |
609 | static int |
610 | linux_supports_bts (void) | |
7c97f91e | 611 | { |
a950d57c MM |
612 | static int cached; |
613 | ||
614 | if (cached == 0) | |
615 | { | |
043c3577 | 616 | if (!kernel_supports_bts ()) |
a950d57c | 617 | cached = -1; |
043c3577 | 618 | else if (!cpu_supports_bts ()) |
a950d57c MM |
619 | cached = -1; |
620 | else | |
621 | cached = 1; | |
622 | } | |
623 | ||
624 | return cached > 0; | |
7c97f91e MM |
625 | } |
626 | ||
bc504a31 | 627 | /* Check whether the linux target supports Intel Processor Trace. */ |
b20a6524 MM |
628 | |
629 | static int | |
630 | linux_supports_pt (void) | |
631 | { | |
632 | static int cached; | |
633 | ||
634 | if (cached == 0) | |
635 | { | |
636 | if (!kernel_supports_pt ()) | |
637 | cached = -1; | |
638 | else | |
639 | cached = 1; | |
640 | } | |
641 | ||
642 | return cached > 0; | |
643 | } | |
644 | ||
7c97f91e MM |
645 | /* See linux-btrace.h. */ |
646 | ||
043c3577 MM |
647 | int |
648 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) | |
649 | { | |
650 | switch (format) | |
651 | { | |
652 | case BTRACE_FORMAT_NONE: | |
653 | return 0; | |
654 | ||
655 | case BTRACE_FORMAT_BTS: | |
656 | return linux_supports_bts (); | |
b20a6524 MM |
657 | |
658 | case BTRACE_FORMAT_PT: | |
659 | return linux_supports_pt (); | |
043c3577 MM |
660 | } |
661 | ||
662 | internal_error (__FILE__, __LINE__, _("Unknown branch trace format")); | |
663 | } | |
664 | ||
f4abbc16 | 665 | /* Enable branch tracing in BTS format. */ |
043c3577 | 666 | |
f4abbc16 | 667 | static struct btrace_target_info * |
d33501a5 | 668 | linux_enable_bts (ptid_t ptid, const struct btrace_config_bts *conf) |
7c97f91e | 669 | { |
aadf7753 | 670 | struct perf_event_mmap_page *header; |
7c97f91e | 671 | struct btrace_target_info *tinfo; |
f4abbc16 | 672 | struct btrace_tinfo_bts *bts; |
e7b01ce0 MM |
673 | size_t size, pages; |
674 | __u64 data_offset; | |
d0fa7535 | 675 | int pid, pg; |
7c97f91e | 676 | |
8d749320 | 677 | tinfo = XCNEW (struct btrace_target_info); |
7c97f91e MM |
678 | tinfo->ptid = ptid; |
679 | ||
f4abbc16 MM |
680 | tinfo->conf.format = BTRACE_FORMAT_BTS; |
681 | bts = &tinfo->variant.bts; | |
7c97f91e | 682 | |
f4abbc16 MM |
683 | bts->attr.size = sizeof (bts->attr); |
684 | bts->attr.type = PERF_TYPE_HARDWARE; | |
685 | bts->attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS; | |
686 | bts->attr.sample_period = 1; | |
7c97f91e | 687 | |
f4abbc16 MM |
688 | /* We sample from and to address. */ |
689 | bts->attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR; | |
7c97f91e | 690 | |
f4abbc16 MM |
691 | bts->attr.exclude_kernel = 1; |
692 | bts->attr.exclude_hv = 1; | |
693 | bts->attr.exclude_idle = 1; | |
7c97f91e MM |
694 | |
695 | pid = ptid_get_lwp (ptid); | |
696 | if (pid == 0) | |
697 | pid = ptid_get_pid (ptid); | |
698 | ||
699 | errno = 0; | |
f4abbc16 MM |
700 | bts->file = syscall (SYS_perf_event_open, &bts->attr, pid, -1, -1, 0); |
701 | if (bts->file < 0) | |
b20a6524 | 702 | goto err_out; |
7c97f91e | 703 | |
d33501a5 | 704 | /* Convert the requested size in bytes to pages (rounding up). */ |
e7b01ce0 MM |
705 | pages = ((size_t) conf->size / PAGE_SIZE |
706 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
d33501a5 MM |
707 | /* We need at least one page. */ |
708 | if (pages == 0) | |
709 | pages = 1; | |
710 | ||
711 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
712 | to the next power of two. */ | |
e7b01ce0 MM |
713 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
714 | if ((pages & ((size_t) 1 << pg)) != 0) | |
715 | pages += ((size_t) 1 << pg); | |
d33501a5 MM |
716 | |
717 | /* We try to allocate the requested size. | |
718 | If that fails, try to get as much as we can. */ | |
719 | for (; pages > 0; pages >>= 1) | |
d0fa7535 | 720 | { |
d33501a5 | 721 | size_t length; |
e7b01ce0 | 722 | __u64 data_size; |
d33501a5 | 723 | |
e7b01ce0 MM |
724 | data_size = (__u64) pages * PAGE_SIZE; |
725 | ||
726 | /* Don't ask for more than we can represent in the configuration. */ | |
727 | if ((__u64) UINT_MAX < data_size) | |
728 | continue; | |
729 | ||
730 | size = (size_t) data_size; | |
d33501a5 MM |
731 | length = size + PAGE_SIZE; |
732 | ||
733 | /* Check for overflows. */ | |
e7b01ce0 | 734 | if ((__u64) length != data_size + PAGE_SIZE) |
d33501a5 MM |
735 | continue; |
736 | ||
d0fa7535 | 737 | /* The number of pages we request needs to be a power of two. */ |
224c3ddb SM |
738 | header = ((struct perf_event_mmap_page *) |
739 | mmap (NULL, length, PROT_READ, MAP_SHARED, bts->file, 0)); | |
aadf7753 MM |
740 | if (header != MAP_FAILED) |
741 | break; | |
d0fa7535 | 742 | } |
7c97f91e | 743 | |
010a18a1 | 744 | if (pages == 0) |
aadf7753 MM |
745 | goto err_file; |
746 | ||
010a18a1 | 747 | data_offset = PAGE_SIZE; |
010a18a1 MM |
748 | |
749 | #if defined (PERF_ATTR_SIZE_VER5) | |
750 | if (offsetof (struct perf_event_mmap_page, data_size) <= header->size) | |
751 | { | |
e7b01ce0 MM |
752 | __u64 data_size; |
753 | ||
010a18a1 MM |
754 | data_offset = header->data_offset; |
755 | data_size = header->data_size; | |
e7b01ce0 MM |
756 | |
757 | size = (unsigned int) data_size; | |
758 | ||
759 | /* Check for overflows. */ | |
760 | if ((__u64) size != data_size) | |
761 | { | |
762 | munmap ((void *) header, size + PAGE_SIZE); | |
763 | goto err_file; | |
764 | } | |
010a18a1 MM |
765 | } |
766 | #endif /* defined (PERF_ATTR_SIZE_VER5) */ | |
767 | ||
f4abbc16 | 768 | bts->header = header; |
010a18a1 | 769 | bts->bts.mem = ((const uint8_t *) header) + data_offset; |
e7b01ce0 | 770 | bts->bts.size = size; |
f4abbc16 | 771 | bts->bts.data_head = &header->data_head; |
e7b01ce0 | 772 | bts->bts.last_head = 0ull; |
aadf7753 | 773 | |
e7b01ce0 | 774 | tinfo->conf.bts.size = (unsigned int) size; |
aadf7753 MM |
775 | return tinfo; |
776 | ||
777 | err_file: | |
d0fa7535 | 778 | /* We were not able to allocate any buffer. */ |
f4abbc16 | 779 | close (bts->file); |
7c97f91e | 780 | |
b20a6524 MM |
781 | err_out: |
782 | xfree (tinfo); | |
783 | return NULL; | |
784 | } | |
785 | ||
786 | #if defined (PERF_ATTR_SIZE_VER5) | |
787 | ||
bc504a31 | 788 | /* Enable branch tracing in Intel Processor Trace format. */ |
b20a6524 MM |
789 | |
790 | static struct btrace_target_info * | |
791 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
792 | { | |
793 | struct perf_event_mmap_page *header; | |
794 | struct btrace_target_info *tinfo; | |
795 | struct btrace_tinfo_pt *pt; | |
e7b01ce0 | 796 | size_t pages, size; |
b20a6524 MM |
797 | int pid, pg, errcode, type; |
798 | ||
799 | if (conf->size == 0) | |
800 | return NULL; | |
801 | ||
802 | errcode = perf_event_pt_event_type (&type); | |
803 | if (errcode != 0) | |
804 | return NULL; | |
805 | ||
806 | pid = ptid_get_lwp (ptid); | |
807 | if (pid == 0) | |
808 | pid = ptid_get_pid (ptid); | |
809 | ||
8d749320 | 810 | tinfo = XCNEW (struct btrace_target_info); |
b20a6524 | 811 | tinfo->ptid = ptid; |
b20a6524 MM |
812 | |
813 | tinfo->conf.format = BTRACE_FORMAT_PT; | |
814 | pt = &tinfo->variant.pt; | |
815 | ||
816 | pt->attr.size = sizeof (pt->attr); | |
817 | pt->attr.type = type; | |
818 | ||
819 | pt->attr.exclude_kernel = 1; | |
820 | pt->attr.exclude_hv = 1; | |
821 | pt->attr.exclude_idle = 1; | |
822 | ||
823 | errno = 0; | |
824 | pt->file = syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0); | |
825 | if (pt->file < 0) | |
826 | goto err; | |
827 | ||
828 | /* Allocate the configuration page. */ | |
a55515ee SM |
829 | header = ((struct perf_event_mmap_page *) |
830 | mmap (NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, | |
831 | pt->file, 0)); | |
b20a6524 MM |
832 | if (header == MAP_FAILED) |
833 | goto err_file; | |
834 | ||
835 | header->aux_offset = header->data_offset + header->data_size; | |
836 | ||
837 | /* Convert the requested size in bytes to pages (rounding up). */ | |
e7b01ce0 MM |
838 | pages = ((size_t) conf->size / PAGE_SIZE |
839 | + ((conf->size % PAGE_SIZE) == 0 ? 0 : 1)); | |
b20a6524 MM |
840 | /* We need at least one page. */ |
841 | if (pages == 0) | |
842 | pages = 1; | |
843 | ||
844 | /* The buffer size can be requested in powers of two pages. Adjust PAGES | |
845 | to the next power of two. */ | |
e7b01ce0 MM |
846 | for (pg = 0; pages != ((size_t) 1 << pg); ++pg) |
847 | if ((pages & ((size_t) 1 << pg)) != 0) | |
848 | pages += ((size_t) 1 << pg); | |
b20a6524 MM |
849 | |
850 | /* We try to allocate the requested size. | |
851 | If that fails, try to get as much as we can. */ | |
852 | for (; pages > 0; pages >>= 1) | |
853 | { | |
854 | size_t length; | |
e7b01ce0 | 855 | __u64 data_size; |
b20a6524 | 856 | |
e7b01ce0 MM |
857 | data_size = (__u64) pages * PAGE_SIZE; |
858 | ||
859 | /* Don't ask for more than we can represent in the configuration. */ | |
860 | if ((__u64) UINT_MAX < data_size) | |
861 | continue; | |
862 | ||
863 | size = (size_t) data_size; | |
b20a6524 MM |
864 | |
865 | /* Check for overflows. */ | |
e7b01ce0 | 866 | if ((__u64) size != data_size) |
b20a6524 MM |
867 | continue; |
868 | ||
e7b01ce0 MM |
869 | header->aux_size = data_size; |
870 | length = size; | |
b20a6524 | 871 | |
a55515ee SM |
872 | pt->pt.mem = ((const uint8_t *) |
873 | mmap (NULL, length, PROT_READ, MAP_SHARED, pt->file, | |
874 | header->aux_offset)); | |
b20a6524 MM |
875 | if (pt->pt.mem != MAP_FAILED) |
876 | break; | |
877 | } | |
878 | ||
879 | if (pages == 0) | |
880 | goto err_conf; | |
881 | ||
882 | pt->header = header; | |
883 | pt->pt.size = size; | |
884 | pt->pt.data_head = &header->aux_head; | |
885 | ||
e7b01ce0 | 886 | tinfo->conf.pt.size = (unsigned int) size; |
b20a6524 MM |
887 | return tinfo; |
888 | ||
889 | err_conf: | |
890 | munmap((void *) header, PAGE_SIZE); | |
891 | ||
892 | err_file: | |
893 | close (pt->file); | |
894 | ||
7c97f91e MM |
895 | err: |
896 | xfree (tinfo); | |
897 | return NULL; | |
898 | } | |
899 | ||
b20a6524 MM |
900 | #else /* !defined (PERF_ATTR_SIZE_VER5) */ |
901 | ||
902 | static struct btrace_target_info * | |
903 | linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf) | |
904 | { | |
905 | errno = EOPNOTSUPP; | |
906 | return NULL; | |
907 | } | |
908 | ||
909 | #endif /* !defined (PERF_ATTR_SIZE_VER5) */ | |
910 | ||
7c97f91e MM |
911 | /* See linux-btrace.h. */ |
912 | ||
f4abbc16 MM |
913 | struct btrace_target_info * |
914 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
915 | { | |
916 | struct btrace_target_info *tinfo; | |
917 | ||
918 | tinfo = NULL; | |
919 | switch (conf->format) | |
920 | { | |
921 | case BTRACE_FORMAT_NONE: | |
922 | break; | |
923 | ||
924 | case BTRACE_FORMAT_BTS: | |
d33501a5 | 925 | tinfo = linux_enable_bts (ptid, &conf->bts); |
f4abbc16 | 926 | break; |
b20a6524 MM |
927 | |
928 | case BTRACE_FORMAT_PT: | |
929 | tinfo = linux_enable_pt (ptid, &conf->pt); | |
930 | break; | |
f4abbc16 MM |
931 | } |
932 | ||
933 | return tinfo; | |
934 | } | |
935 | ||
936 | /* Disable BTS tracing. */ | |
937 | ||
938 | static enum btrace_error | |
939 | linux_disable_bts (struct btrace_tinfo_bts *tinfo) | |
7c97f91e | 940 | { |
aadf7753 | 941 | munmap((void *) tinfo->header, tinfo->bts.size + PAGE_SIZE); |
7c97f91e | 942 | close (tinfo->file); |
7c97f91e | 943 | |
969c39fb | 944 | return BTRACE_ERR_NONE; |
7c97f91e MM |
945 | } |
946 | ||
bc504a31 | 947 | /* Disable Intel Processor Trace tracing. */ |
b20a6524 MM |
948 | |
949 | static enum btrace_error | |
950 | linux_disable_pt (struct btrace_tinfo_pt *tinfo) | |
951 | { | |
952 | munmap((void *) tinfo->pt.mem, tinfo->pt.size); | |
953 | munmap((void *) tinfo->header, PAGE_SIZE); | |
954 | close (tinfo->file); | |
955 | ||
956 | return BTRACE_ERR_NONE; | |
957 | } | |
958 | ||
f4abbc16 MM |
959 | /* See linux-btrace.h. */ |
960 | ||
961 | enum btrace_error | |
962 | linux_disable_btrace (struct btrace_target_info *tinfo) | |
963 | { | |
964 | enum btrace_error errcode; | |
965 | ||
966 | errcode = BTRACE_ERR_NOT_SUPPORTED; | |
967 | switch (tinfo->conf.format) | |
968 | { | |
969 | case BTRACE_FORMAT_NONE: | |
970 | break; | |
971 | ||
972 | case BTRACE_FORMAT_BTS: | |
973 | errcode = linux_disable_bts (&tinfo->variant.bts); | |
974 | break; | |
b20a6524 MM |
975 | |
976 | case BTRACE_FORMAT_PT: | |
977 | errcode = linux_disable_pt (&tinfo->variant.pt); | |
978 | break; | |
f4abbc16 MM |
979 | } |
980 | ||
981 | if (errcode == BTRACE_ERR_NONE) | |
982 | xfree (tinfo); | |
983 | ||
984 | return errcode; | |
985 | } | |
986 | ||
734b0e4b MM |
987 | /* Read branch trace data in BTS format for the thread given by TINFO into |
988 | BTRACE using the TYPE reading method. */ | |
7c97f91e | 989 | |
734b0e4b MM |
990 | static enum btrace_error |
991 | linux_read_bts (struct btrace_data_bts *btrace, | |
992 | struct btrace_target_info *tinfo, | |
993 | enum btrace_read_type type) | |
7c97f91e | 994 | { |
aadf7753 | 995 | struct perf_event_buffer *pevent; |
7c97f91e | 996 | const uint8_t *begin, *end, *start; |
e7b01ce0 MM |
997 | size_t buffer_size, size; |
998 | __u64 data_head, data_tail; | |
aadf7753 MM |
999 | unsigned int retries = 5; |
1000 | ||
f4abbc16 | 1001 | pevent = &tinfo->variant.bts.bts; |
7c97f91e | 1002 | |
969c39fb MM |
1003 | /* For delta reads, we return at least the partial last block containing |
1004 | the current PC. */ | |
aadf7753 | 1005 | if (type == BTRACE_READ_NEW && !perf_event_new_data (pevent)) |
969c39fb | 1006 | return BTRACE_ERR_NONE; |
7c97f91e | 1007 | |
aadf7753 MM |
1008 | buffer_size = pevent->size; |
1009 | data_tail = pevent->last_head; | |
7c97f91e MM |
1010 | |
1011 | /* We may need to retry reading the trace. See below. */ | |
1012 | while (retries--) | |
1013 | { | |
aadf7753 | 1014 | data_head = *pevent->data_head; |
7c97f91e | 1015 | |
ed9edfb5 | 1016 | /* Delete any leftover trace from the previous iteration. */ |
734b0e4b | 1017 | VEC_free (btrace_block_s, btrace->blocks); |
ed9edfb5 | 1018 | |
969c39fb | 1019 | if (type == BTRACE_READ_DELTA) |
7c97f91e | 1020 | { |
e7b01ce0 MM |
1021 | __u64 data_size; |
1022 | ||
969c39fb MM |
1023 | /* Determine the number of bytes to read and check for buffer |
1024 | overflows. */ | |
1025 | ||
1026 | /* Check for data head overflows. We might be able to recover from | |
1027 | those but they are very unlikely and it's not really worth the | |
1028 | effort, I think. */ | |
1029 | if (data_head < data_tail) | |
1030 | return BTRACE_ERR_OVERFLOW; | |
1031 | ||
1032 | /* If the buffer is smaller than the trace delta, we overflowed. */ | |
e7b01ce0 MM |
1033 | data_size = data_head - data_tail; |
1034 | if (buffer_size < data_size) | |
969c39fb | 1035 | return BTRACE_ERR_OVERFLOW; |
e7b01ce0 MM |
1036 | |
1037 | /* DATA_SIZE <= BUFFER_SIZE and therefore fits into a size_t. */ | |
1038 | size = (size_t) data_size; | |
969c39fb MM |
1039 | } |
1040 | else | |
1041 | { | |
1042 | /* Read the entire buffer. */ | |
1043 | size = buffer_size; | |
7c97f91e | 1044 | |
969c39fb MM |
1045 | /* Adjust the size if the buffer has not overflowed, yet. */ |
1046 | if (data_head < size) | |
e7b01ce0 | 1047 | size = (size_t) data_head; |
7c97f91e MM |
1048 | } |
1049 | ||
969c39fb | 1050 | /* Data_head keeps growing; the buffer itself is circular. */ |
aadf7753 | 1051 | begin = pevent->mem; |
969c39fb MM |
1052 | start = begin + data_head % buffer_size; |
1053 | ||
1054 | if (data_head <= buffer_size) | |
1055 | end = start; | |
1056 | else | |
aadf7753 | 1057 | end = begin + pevent->size; |
969c39fb | 1058 | |
734b0e4b | 1059 | btrace->blocks = perf_event_read_bts (tinfo, begin, end, start, size); |
969c39fb | 1060 | |
7c97f91e MM |
1061 | /* The stopping thread notifies its ptracer before it is scheduled out. |
1062 | On multi-core systems, the debugger might therefore run while the | |
1063 | kernel might be writing the last branch trace records. | |
1064 | ||
1065 | Let's check whether the data head moved while we read the trace. */ | |
aadf7753 | 1066 | if (data_head == *pevent->data_head) |
7c97f91e MM |
1067 | break; |
1068 | } | |
1069 | ||
aadf7753 | 1070 | pevent->last_head = data_head; |
7c97f91e | 1071 | |
969c39fb MM |
1072 | /* Prune the incomplete last block (i.e. the first one of inferior execution) |
1073 | if we're not doing a delta read. There is no way of filling in its zeroed | |
1074 | BEGIN element. */ | |
734b0e4b MM |
1075 | if (!VEC_empty (btrace_block_s, btrace->blocks) |
1076 | && type != BTRACE_READ_DELTA) | |
1077 | VEC_pop (btrace_block_s, btrace->blocks); | |
969c39fb MM |
1078 | |
1079 | return BTRACE_ERR_NONE; | |
7c97f91e MM |
1080 | } |
1081 | ||
bc504a31 | 1082 | /* Fill in the Intel Processor Trace configuration information. */ |
b20a6524 MM |
1083 | |
1084 | static void | |
1085 | linux_fill_btrace_pt_config (struct btrace_data_pt_config *conf) | |
1086 | { | |
1087 | conf->cpu = btrace_this_cpu (); | |
1088 | } | |
1089 | ||
bc504a31 | 1090 | /* Read branch trace data in Intel Processor Trace format for the thread |
b20a6524 MM |
1091 | given by TINFO into BTRACE using the TYPE reading method. */ |
1092 | ||
1093 | static enum btrace_error | |
1094 | linux_read_pt (struct btrace_data_pt *btrace, | |
1095 | struct btrace_target_info *tinfo, | |
1096 | enum btrace_read_type type) | |
1097 | { | |
1098 | struct perf_event_buffer *pt; | |
1099 | ||
1100 | pt = &tinfo->variant.pt.pt; | |
1101 | ||
1102 | linux_fill_btrace_pt_config (&btrace->config); | |
1103 | ||
1104 | switch (type) | |
1105 | { | |
1106 | case BTRACE_READ_DELTA: | |
1107 | /* We don't support delta reads. The data head (i.e. aux_head) wraps | |
1108 | around to stay inside the aux buffer. */ | |
1109 | return BTRACE_ERR_NOT_SUPPORTED; | |
1110 | ||
1111 | case BTRACE_READ_NEW: | |
1112 | if (!perf_event_new_data (pt)) | |
1113 | return BTRACE_ERR_NONE; | |
1114 | ||
1115 | /* Fall through. */ | |
1116 | case BTRACE_READ_ALL: | |
1117 | perf_event_read_all (pt, &btrace->data, &btrace->size); | |
1118 | return BTRACE_ERR_NONE; | |
1119 | } | |
1120 | ||
1121 | internal_error (__FILE__, __LINE__, _("Unkown btrace read type.")); | |
1122 | } | |
1123 | ||
734b0e4b MM |
1124 | /* See linux-btrace.h. */ |
1125 | ||
1126 | enum btrace_error | |
1127 | linux_read_btrace (struct btrace_data *btrace, | |
1128 | struct btrace_target_info *tinfo, | |
1129 | enum btrace_read_type type) | |
1130 | { | |
f4abbc16 MM |
1131 | switch (tinfo->conf.format) |
1132 | { | |
1133 | case BTRACE_FORMAT_NONE: | |
1134 | return BTRACE_ERR_NOT_SUPPORTED; | |
1135 | ||
1136 | case BTRACE_FORMAT_BTS: | |
1137 | /* We read btrace in BTS format. */ | |
1138 | btrace->format = BTRACE_FORMAT_BTS; | |
1139 | btrace->variant.bts.blocks = NULL; | |
1140 | ||
1141 | return linux_read_bts (&btrace->variant.bts, tinfo, type); | |
b20a6524 MM |
1142 | |
1143 | case BTRACE_FORMAT_PT: | |
bc504a31 | 1144 | /* We read btrace in Intel Processor Trace format. */ |
b20a6524 MM |
1145 | btrace->format = BTRACE_FORMAT_PT; |
1146 | btrace->variant.pt.data = NULL; | |
1147 | btrace->variant.pt.size = 0; | |
1148 | ||
1149 | return linux_read_pt (&btrace->variant.pt, tinfo, type); | |
f4abbc16 MM |
1150 | } |
1151 | ||
1152 | internal_error (__FILE__, __LINE__, _("Unkown branch trace format.")); | |
1153 | } | |
1154 | ||
1155 | /* See linux-btrace.h. */ | |
734b0e4b | 1156 | |
f4abbc16 MM |
1157 | const struct btrace_config * |
1158 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1159 | { | |
1160 | return &tinfo->conf; | |
734b0e4b MM |
1161 | } |
1162 | ||
7c97f91e MM |
1163 | #else /* !HAVE_LINUX_PERF_EVENT_H */ |
1164 | ||
1165 | /* See linux-btrace.h. */ | |
1166 | ||
1167 | int | |
043c3577 | 1168 | linux_supports_btrace (struct target_ops *ops, enum btrace_format format) |
7c97f91e MM |
1169 | { |
1170 | return 0; | |
1171 | } | |
1172 | ||
1173 | /* See linux-btrace.h. */ | |
1174 | ||
1175 | struct btrace_target_info * | |
f4abbc16 | 1176 | linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf) |
7c97f91e MM |
1177 | { |
1178 | return NULL; | |
1179 | } | |
1180 | ||
1181 | /* See linux-btrace.h. */ | |
1182 | ||
969c39fb | 1183 | enum btrace_error |
7c97f91e MM |
1184 | linux_disable_btrace (struct btrace_target_info *tinfo) |
1185 | { | |
969c39fb | 1186 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1187 | } |
1188 | ||
1189 | /* See linux-btrace.h. */ | |
1190 | ||
969c39fb | 1191 | enum btrace_error |
734b0e4b | 1192 | linux_read_btrace (struct btrace_data *btrace, |
969c39fb | 1193 | struct btrace_target_info *tinfo, |
7c97f91e MM |
1194 | enum btrace_read_type type) |
1195 | { | |
969c39fb | 1196 | return BTRACE_ERR_NOT_SUPPORTED; |
7c97f91e MM |
1197 | } |
1198 | ||
f4abbc16 MM |
1199 | /* See linux-btrace.h. */ |
1200 | ||
1201 | const struct btrace_config * | |
1202 | linux_btrace_conf (const struct btrace_target_info *tinfo) | |
1203 | { | |
1204 | return NULL; | |
1205 | } | |
1206 | ||
7c97f91e | 1207 | #endif /* !HAVE_LINUX_PERF_EVENT_H */ |